Intake Rehab: How Wilson Manifolds Restores Trashed Factory Intakes

Keith Wilson and his crew are magicians of sorts. They routinely create some of the most amazing sheet-aluminum intake creations on earth. We’ve seen examples of the shop’s work that could be just as much at home in a fine-arts museum instead of sitting on top of a 2,000-horsepower race engine. These manifolds come very close to the perfect confluence between form and function. However, that’s not what this story is about.

This story is a bit more demure, but no less impressive. A still-popular push is reclaiming muscle machines from the past and resurrecting them to as-new. Wilson Manifolds is doing its part in that process by resurrecting old factory aluminum intakes to like-new condition.

Our original intake (left) was a decent shape with a few noticeable cosmetic flaws. Wilson says that even manifolds with broken and/or missing corners can be repaired. The close-up on the right reveals our Z28 intake’s 3917610 casting number as well as visual evidence that the coil mount had been heavily mangled. Despite this damage, Wilson commented that our intake was one of the better ones he’s seen.

We decided to put that idea to the test by sending them a tantalizingly grungy example of a small-block Chevy intake manifold that was destined to sit atop an original 1967 302ci Z28 engine. Our manifold had been subjected to 50 years of abuses and was in need of restoration and we couldn’t think of a better place to send it for that intensive care than Wilson Manifolds.

Assessing The Condition

Upon arrival, Keith Wilson called and from our description, he was expecting something much worse than what arrived. “Yours is one of the better ones we’ve seen. This will be easy. Some of the stuff we get is really pretty nasty,” said Wilson.

All production small-block aluminum manifolds came with this stamped steel heat deflector (left) riveted into place on the lifter valley side of the manifold. This prevents hot oil from baking onto the heat crossover passage. This porosity damage (right) was probably the worst damage to our intake but the Wilson people passed it off as just another day behind the TIG torch. Their repair was seamless.

We were encouraged by that, but were still anxious to see what could be done with our corroded example of 1967 intake manifold technology. In order to completely clean the intake, Wilson carefully removed the four small rivets that retain the heat shield. One advantage to this is that we were able to verify the manifold’s date code as appropriate for our 1967 engine. This was reinforced by the “3917610” casting number on the manifold’s top side, which our research indicated was originally intended for the Z28 engines for 1967 and 1968.

Our manifold had been mistreated where the original ignition coil was mounted and that area was going to need some surgery. The area where most Chevrolet aluminum manifolds corrode is the shelf for the thermostat. This is where two dissimilar metals are located, which tends to accelerate the electrolysis process. The softer aluminum gives up electrons, creating pitting and corrosion. We’ve seen manifolds where this shelf has all but disappeared, making a repair difficult.

(Left) This is an “after” view of our intake once Wilson had completed their efforts. The porosity issues were completely repaired and the damage to the coil mounts appeared as if they had never been there. (Right) All Chevrolet aluminum intakes sport this Winters foundry “snowflake” casting mark. Poorly executed restorations often obscure the mark due to overzealous blasting. Wilson’s approach removes no metal from the intake yet restores the intake’s original appearance.

Our manifold was in good condition since it had been separated from the engine for several decades, saving it from the aluminum-eating corrosion monster. However, Wilson assured us that even if that thermostat shelf has been heavily damaged, his TIG-weld artists can quickly build this area up and then machine it back to OE condition.

In another example, a customer delivered a similar small-block dual-plane manifold that had been thoroughly molested. The most obvious issue was the plenum divider had been completely removed by a previous owner. The manifold was going back on a 1965 Corvette and the owner wanted the plenum wall reinstated, which is exactly what the Wilson crew achieved. This is just one sample of the kind of magic that the Wilson guys create on a daily basis.

This bottom side shot (left) with the heat shield removed revealed the date code cast into the manifold. Ours was very difficult to read but appears to indicate a 1966 casting date. Wilson left the heat shield off so we could document the date. This vertical view into the plenum (right) reveals the work goes far deeper than just the cosmetics to the exterior.

More Than Just Looks

Beyond just restoration, Wilson can also perform internal modifications that can drastically enhance the performance of older intakes. For example, there is some minor excitement created right now with the Factory Appearing Stock Tire (F.A.S.T.) drag classes where the car – and especially the engine – must appear stock from the outside. Internal modifications like added displacement, roller cams, major cylinder head modifications, and intake manifold porting is legal as long as the external appearances remain stock. Wilson says that many of the top F.A.S.T. cars benefit from Wilson upgrades.

Wilson’s rehab of our manifold required only a short time to complete. Our timing was such that Wilson used our manifold as part of his display at the 2018 PRI show alongside several of the jewel-like creations they pull off on a weekly basis. So if you’re looking to have an original intake manifold restored, we can’t think of a better place to send it than to the artists at Wilson Manifolds.

This customer-supplied dual plane suffered far more damage than our intake (upper left, inset) but was only a minor challenge to return it to hero status. Note the missing plenum wall divider in the inset photo and how it has been totally restored.

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About the author

Jeff Smith

Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.